i havent tried 300 zx seats but have in the works a rear seat from a firebird/camero 82-02.looke like the t.d. stock seat with a one piece back ans separate buckets. having just started to drive my fiberfab, i understand how good seat are needed. like sitting on bare plywood. some guys are cutting the center form the plywood and putting in springs and webbing with some sucess ive done some test fitting with some leather camero rear seats and so far the back is too high but is really comfy and looks good. i will continue my experiments after i get all the basics(brakes, electrical etc) done. in sure there are seats somewhere that will just bolt in .
I don’t know the manufacturer of my seats, but they are early compact car. They are old enough that they have never had a headrest. I’m guessing that they might be early Pinto. I also don’t have the seat box base, they set right on the floor. Quite comfortable, have taken several 100-200 mile trips without butt pain. They sit as far back as they can, and are fine for me, but I’m short. The thickness of the back is therefore important for you long and lanky types!